2012 news review: The year's biggest surprises

Which world events surprised us most in 2012? The Observer's news team pick the ones nobody saw coming

Chancellor George Osborne announces the date of next year's March budget outside No 11 Downing Street earlier this month. He will be hoping it serves him better than 2012's 'omnishambles'. Photograph: Lewis Whyld/PA

Politics

The decline and fall (almost) of George Osborne Whatever you might have thought of George Osborne a year ago, he began 2012 with a pretty decent reputation in Westminster as a political strategist. Then came his March budget – an "omnishambles" that unravelled day after day and all but destroyed Osborne's career with it. It was the politics, more than the economics, that were awful. The decision to drop the upper (50p) rate of tax in the thick of painful austerity at the same time as imposing taxes on pasties, caravans and even charity donations (the spring from which the "big society" was supposed to be watered) was a catastrophe and a gift for Labour.

The EU wins the Nobel peace prize In October, like manna in the depth of famine, the EU was awarded the Nobel peace prize for six decades of ceaseless, tireless work in pursuit of unity in Europe. In the UK, eurosceptics condemned the award, while in Brussels it was accepted as proof that occasionally something good can lighten the darkness in the midst of the eurozone crisis. Stunned and a little wrong-footed, David Cameron suggested that rather than him attending the acceptance ceremony, the EU should send along a group of schoolchildren instead. Toby Helm, political editor

Arts

Tony Hall returns to the BBC Tony Hall led the Royal Opera House out of its dark days of embarrassing cultural exclusivity into its current sunlit position as an institution with a loud voice in the arguments over arts policy. He even helped create a few affordable seats in the auditorium at Covent Garden for the fleet of foot. But, despite his success at the head of the Cultural Olympiad, it seemed highly unlikely Hall would one day return, triumphant, to his original home at the BBC to become director general where he once led the news department.

The triumph of public art In a cynical age, and at a time when every penny must be counted, the success of the wilder edges of the public art scene is a happy mystery. The eccentric Olympic opening ceremony is now being name-checked everywhere, by businesses, by politicians and by those calling for arts funding to be protected from savage cuts. In culture, if not in city finance, risks are clearly worth taking for the good of the country. Even Damien Hirst's controversial statue of Verity in Ilfracombe harbour has been broadly welcomed. Art has become part of public life just at the moment it is in danger of being pushed out of the school syllabus. Vanessa Thorpe, arts editor

World

Grexit, the dog that didn't bark This was supposed to be the year of the Greek exit from the EU – or Grexit – which, if you read many commentators earlier in the year was supposed to lead to Eurogeddon in some guise. This turned out (for now at least) to be about as accurate as predictions of the Mayan apocalypse this month.

The fall from grace of David Petraeus Who could have predicted the staggering lack of judgment shown by David Petraeus? Not only did the CIA head have an affair with Paula Broadwell, his biographer, whom he allowed to accompany him to Afghanistan, but he was also involved in a social menage more appropriate to the Wisteria Lane of Desperate Housewives than tight-lipped Langley. Peter Beaumont, foreign ediotor

Science

Junk DNA is vital Stretches of DNA previously dismissed as "junk" are in fact crucial to the working of our genomes, researchers announced in September. The discovery by the international Encode project represents a radical reappraisal of the operation of DNA. For years, it was assumed our bodies are controlled by only a few genes. The rest was known as junk DNA. But Encode found large regions of this material helps regulate our health, opening up the prospect of developing new treatments for heart disease, diabetes and other conditions.

There is a world with four suns Astronomers have identified a world with four suns, it was announced in October. The planet, known as PH1, is almost 5,000 light years away and is believed to be six times the size of Earth. It orbits one pair of stars and is in turn circled by a second pair, meaning four stars light up its skies. "Imagine what it would be like to visit a planet with four suns in its sky," Dr Chris Lintott, of Oxford University, told PA. However, the new world is confusing for astronomers, he added."It's not at all clear how it formed in such a busy environment." Robin McKie, science editor